Process of sterilizing milk cream, beverages, and other alimentary substances.



ALFRED BUTTER, F MEN'IONE, VICTORIA, AUSTRALIA.

PROCESS OF STERILIZINQ MILK,

CREAM, BEVERAGES, afiND OTHER ALIMIENTARY Patented May 25, 1915.

' SUBSTANCES.

1340 71 7 Specification of Letters Patent. No Drawing. Application filedDecember 19, 1913. Serial no. 807,692.

To all whom it M ay concern Be it known that I, ALrREn BUTTER,- A. R. C.So, a subject of the King of Great Britain, residing at Marlton,Florence street, Mentone, in the' State of -Victoria, Australia,analytical chemist, have invented a Process of sterilizing Milk, Cream,Beverages, and other Alimentary Substances, of which the following isaspecification.

This invention has for its object the destruction of the micro-organismsin milk,

cream and other alimentary substances and beverages in such a manner asto economize the cost, increase the utility and widen the scope of theprocess and enable the substance treated to be received by the consumerin a sterilized condition andfree from contamination and lesssusceptible to deterioration but without having its taste or nutritiveor digestive qualities impaired.

It is well known that nascent oxygen and ozone have a very destructiveeffect on micro-organisms and attempts have been made to industriallyapply nascent oxygen for such purposes by the employment of peroxid ofhydrogen either directly or by chemical action. Peroxid of hydrogenhowever is of an unstable character and liable to quickly deterioratebesides which its presence in any quantity other than a trace isundesirable, and moreover it does not effectively sterilize except inundesirable quantities. The substances employed in this invention arestable at ordinary temperatures when kept in tubes away from moistureand air and by the use of this invention the object mentioned above canbe attained in respect of many alimentary substances, and the excess ofhydrogen peroxid, if any, is a minimized amount, and is so controlledthat it is a secondary consideration to the production of oxygen to themaximum amount. For instance, alkalis, heat, ferments, catalysts,reducing agents and a low pressure are agencies which promote thedecomposition of hydrogen'peroxid and act against its formation, whereasin prior proposed processes the conditions which obtained both asregards method and material were such as to favor the production ofhydrogen peroxid to the maximum degree, the use of hermetically "sealedvessels with slow action materials tending not only to produce a maximumof hydrogen peroxid, but also preventing the decomposition of thehydrogen peroxid molecule. This is responsible for a considerable excessof hydrogen peroxid in the resultant product, which is exceedinglydifficult of removal. Moreover, the production of solid precipitates inmilk, beverages, and

alimentary substances generally is disadvantageous on commercial andphysiological grounds and the production of soluble matters is eminentlynecessary.

It is desirable that the process be carried out in vessels wherein thesubstance under treatment is protected from contamination during andafter the operation and that the process be conducted under atmosphericpressure, a condition which favors the breaking down of the hydrogenperoxid molecule into water and oxygen.

I have found that by the introduction into the substances to be treatedof a small proportion of the peroxid of such an alkali metal or alkalineearth metal as may without injurious or detrimental effect be introducedinto the substances to be treated so that reaction will ensue with acidsin the substances to be treated and (or) with one of the acids allowableto be introduced under the process hereinafter set forth and by theadoption of the process as hereinafter directed the destruction can beachieved of the micro-organisms in milk and cream and in some otheralimentary substances in such a manner as to enable the substancetreated to be received by the consumer in a sterilized condition freefrom contamination and less susceptible to deterioration and withoutimpairing the taste or nutritive or digestive qualities of suchsubstances.

Described in general terms my process is as follows A very smallproportion of sodium peroxid as previously mentioned but preferablysodium peroxid is gradually addedto the substance for treatment and isthoroughly mingled therewith by constant stirring or agitation forthe'purpose of rapidly producing nascent oxygen and (or) ozone whenheated in a vessel under ordinary atmospheric pressure. Unless thesubstance under treatment contains suflicient acid to neutralize oralmost neutralize the alkali in the peroxid, an amount of some suitableacid (that is to say, an acid which when combined with the base of theperoxid will yield a salt which in the amount produced will have noinjurious or detrimental effect upon the substance under treatment) suchas citric phosphoric carbonic or sulfuric should be added. The substanceunder treatment should then be gradually warmed to and maintained at atemperature exceeding 30 C. and which may require to be varied inaccordance with the nature and quality of such substance and for aperiod of time which may also require to be varied in like manner. Thetemperature should not be allowed to rise to a degree which wouldprejudicially affect-the taste or impair the nutritive or digestivequalities of the substance under treatment," but subject to thiscondition should be as high as practicable. The amount of peroxid usedmust be as nearly as possible just sufficient to generate the requisitequantity of nascent oxygen and (or) ozone to destroy the micro-organismsin the substance under treatment. Should the acid naturally present inthe substance to be treated be sufficient to fully neutralize or morethan neutralize the alkali in the peroxid introduced carbonate of sodaor the like may sometimes be used withgood effect to reduce the acidity.

The process may be varied by first warming the substance to be treatedbefore adding any of the materials and applying the process as describedabove.

Having .in general terms described the process I will now moreparticularly describe its application in certain particular cases: Inthe case of milk gradually add from about 0.05 per cent. to about 0.15per cent. by weight (in proportion to the degree of deterioration of themilk) of sodium peroxid with constant stirring. If the milk after suchaddition and stirring is alkaline, immediately add .an amount of citricor other suitable acid as mentioned above, in quantity just sufficientto almost neutralize the alkalinity. The degree of alkalinity of themilk may be determined by titration and the quantity of acid requiredcalculated from the chemical reaction. If

the milk to be treated is free from acid and citric acid is employed inthe process, 1.6 parts of citric acid to every part of sodium peroxidshould be added as the sodium peroxid will thus be very slightly inexcess. The milk should be placed in suitable ves sels open toatmospheric pressure but as far as practicable protected fromcontamination in such a manner that air or gases can freely enter orleave the vessel, but all microbes are precluded from contaminating theliquid both during and subsequent to the process. The substance isaccordingly treated at atmospheric pressure and the use of hermeticallysealed vessels is thereby obviated. The milk is then gradually warmed byany suitable means to a temperature approximating to but preferably notexceeding 52 (3., and maintained at that temperature for thirty minutesor more according to the degree of deterioration in the milk. Theprolongation of the time for which the temperature is maintained foreven four or five hours would not prejudicially affect the working ofthe process. The warming of the milk to the temperature mentionedabove-may, if preferred, immediately pre-. cede the application of-theprocess. The presence of lactic or other acid if any in the milk to betreated will dispense with the necessity for the artificial addition ofacid unnecessary by reason of the presence of lactic acid in the ripenedcream. I

In the caseof. grape juices, fruit juices, fruit pulp, beer, aeratedwaters and other beverages the treatment is also substantially the sameas for milk, the amount of sodium peroxid used being approximately .05per cent., and again the use of acid is unnecessary if present 'insuflicient quantity in the product treated.

It will be well understood that in lieu of sodium peroxid, potassiumperoxid, or such other equivalent alkaline peroxid may be used as wellin the presence of an acid when heated rapidly produce nascent oxygenand (or) ozone, and have no injurious or detrimental eflect on thesubstance under treat-' ment.

Having now fully described and ascertained my said invention and themanner in which it is to be performed, I declare that What I claim isI 1. In the sterilization of alimentary liquids, treating such liquidsat atmospheric pressure by gradually adding thereto and thoroughlymingling therewith a small proportion of sodium peroxid, and heating thesaid substance substantially as herein set forth.

2. In the sterilization of alimentary liquids, treating such liquids atatmospheric pressure by gradually adding thereto and thoroughly minglingtherewith small proportions of sodium peroxid and an acid, and heatingthesaid substance, substantially as herein set forth.

'3. The improvements in and relating to the sterilization of alimentaryliquids by my hand in presence of two subscribing witthe productiontherein of nascent oxygen nesses.

and ozone Without the production of hydro- ALFRED BUTTER. gen peroxid toa prejudicial or undesirable Witnesses: 5 extent in the manner hereinspecified. EDWARD N. WA'rlms,

In testimony whereof I have hereunto set WILLIAM G. HOLDEN.

